Automatic fire alarm



Aug. 16, 1955 K. Y. CARR AUTOMATIC FIRE ALARM Filed April 16, 1954 II II III]! II INVENTOR KYCYCL 7"?" ATTORNEYS United States Patent AUTOMATIC FIRE ALARM Keller Y. Carr, Hialeah, Fla.

Application April 16, 1954, Serial No. 423,811

2 Claims. (Cl. 116-102) This invention relates to a fire alarm device.

An object of this invention is to provide a fire alarm device which is active on rise in temperature to a predetermined degree, and which will produce an audible signal in the area in which the device is placed.

Another object of this invention is to provide a fire alarm device which includes a spring motor with a clapper associated therewith and a temperature responsive means connected with the clapper for holding the latter against operation until the air about the device reaches a predetermined maximum.

A further object of this invention is to provide a device of this kind which is simple in construction and can be readily adjusted to operate at any predetermined maximum temperature. Where these devices are placed in buildings it is contemplated that there be a number of these devices placed in various rooms, chambers, or locations in the building so that rise in temperature in any particular part of a building will cause the alarm to operate and thereby give warning that the temperature in a particular area has reached a predetermined maximum.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawing and specification, and then more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is a horizontal section taken through a fire alarm device constructed according to an embodiment of this invention.

Figure 2 is a sectional view taken on the line 22 of Figure 1.

Referring to the drawing, the numeral designates 7 generally a housing which is formed of opposite side walls 11 and 12, a bottom wall 13, a top wall 14, and opposite end walls 15 and 16. The end wall 16 may be removed from the adjacent end of the housing for access to the device and for effecting adjustment of the temperature operated means for changing the operation of the device.

The housing 10 has mounted therein a gear train, generally indicated at 17,'which is carried by a U-shaped frame 18. The gear train 17 is operated by means of a spring motor or power member 19 and a toothed escape wheel 20 is operated from the gear train 17.

A Iockable escape member 21 carried by a shaft 22 has a clapper 23 extending therefrom which upon rotation of wheel 20 is adapted to strike the wall 15. An elongated arcuate balance arm 24 having a balance weight 25 at its outer end extends from escape member 21 oppositely from clapper 23.

The clapper 23 is held normally against operation by means of a pivoted lever 26 which at one end bears against the outer side of arm or balance member 24. The lever 26 is bifurcated at its opposite or outer end, as indicated at 27, and is pivotally mounted on a pivot member 28 which is fixed by fastening means 29 to an upwardly and outwardly projecting bracket arm 30.

2,715,381 Patented Aug. 16, 1955 The arm 30 extends from a base plate 31 which is fixed to the bottom wall 13, and the base plate 31 also has extending from the opposite end thereof an upwardly projecting arm 32.

An expansible bellows or thermostatic member 33 is disposed above the base 31 and is formed with an end head 34 having a stud 35 fixed thereto and projecting through the upright arm 32. The bellows member 33 also includes a forwardly projecting stud 36 which slidably engages through a guide bracket 37 formed with an obtusely angled outer base 38 which is fixed by the fastening means 29 to the bracket arm 30.

The lever 26 is provided with a depressed portion 39 through which the stud 36 engages, and the stud 36 is fixed in the depressed portion 39 by fastening means 40.

The bellows 33 is adapted to contain a temperature sensitive gas which will eifect expansion of the bellows under high temperature so that the lever 26 will be moved outwardly or upwardly as viewed in Figure 1, to effect release of the balance arm 24.

The lever 26 is placed under spring tension so as to hold the lever 26 against release of the balance arm 24 until the bellows 33 has expanded to a maximum by means of a screw shaft 41 which is journalled through a bracket arm 42 extending from the arm 32.

The screw shaft 41 has a knob 43 at its outer end and a nut 44 is threaded on the shaft 41 inwardly from the bracket arm 42. One end of a spring 45 is fixed to the nut 44 and the other end of the spring 45 is fixed to a collar 46 which is secured by fastening means 47 to a rod 48.

The rod 48 extends loosely through an opening 49 formed in lever 26, and a washer or plate 50 is disposed on the outer end of rod 48 and is secured by fastening means 51. The washer or plate 50 is provided with a pair of V-shaped projections 52 which have the apices thereof engaged with the outer side of lever 26.

In the use and operation of this alarm, the alarm is set by means of the knob 43 and screw shaft 41. When the temperature within and about the housing 10 reaches a predetermined maximum, bellows 33 will expand and move lever 26 outwardly against the tension of spring 45 so that balance arm 24 will be released. When arm 24 has been released, escape wheel 20 will rotate and escape member 21 will be rocked thereby and clapper 23 will rapidly strike the adjacent end wall 15.

This alarm will provide an audible signal indicating the existence of a maximum high temperature in the location in which the device is placed, and inasmuch as the device is not connected to any electric circuit the device will operate independently of any electric circuit being burned out or turned oif.

What is claimed is:

1. An automatic fire alarm comprising a housing, a power member in said power housing, a gear train connected to said member, a rockable balance means connected to said gear train, a clapper carried by said balance means and engageable with said housing, a lever, means rockably supporting said lever with an end thereof engageable with said balance means, adjustable spring means engaging said lever to hold said lever in contact with said balance means to thereby hold said balance means inoperative, said adjustable spring means including a screw shaft, coil spring means fixed to said screw shaft, rod means fixed to said coil spring means, said rod means extending through an opening in said lever, and restraining means on said rod means engaging the outer side of said lever, and thermostatic means connected to said lever to move said lever to released position at a predetermined maximum temperature.

2. An automatic fire alarm comprising a housing, spring power means in said housing, a gear train connected to said power means, a rockable balance means connected to and actuated by said gear train, clapper means carried by said balance means and engageable with said housing, lever means engageable with said balance means for-holding said balance means against rocking, adjustablespring means engaging said lever to hold said lever in contact with said balance means'to thereby hold said balance means inoperative, said adjustable spring means including a screw shaft adjustable on said housing, coil spring means fixed to said screw shaft, rod means fixed to said coil spring means, said rod means extending through an opening in said lever, and restraining means on said rod means engaging the outer side of said lever,

and thermostatic bellows means fixed at one end to said housing and adapted to move said lever to a released position at a predetermined maximum temperature, said References Cited in the file of this patent UNITED STATES PATENTS 1,380,009 Overmyer May 3], 1921 1,936,970 Pietzsch Nov. 28, 1933 2,609,785 Fink Sept. 9, 1952 

